Hi Peter,
Looking at your pictures, it seems that you should be able to add a sprocket
to the chain drive in your limit switch area.
I had to do a similar thing to mine a few years back.
My original controller used selsyns until one was creamed by a voltage surge
caused by a huge static burst in a storm.
I could not find a matching selsyn at the time so I went to the conventional
controller approach. I now use a modified CDE controller with a RotorEZ
controller interface to control relays mounted at the base of the tower. The
RotorEZ controller module provides excellent interface to my Logger32
logging program.
My Prop Pitch still has the taper gear attached to the top of the gearbox. I
hand cut a matching gear to drive a 500 ohm potentiometer. I made this from
1/4 in. phenolic flat stock. I had an aluminum gear (Home brewed) that had
the same number of teeth as the prop pitch Gearbox to drive the selsyn, but
when I cut the phenolic gear I increased the size so I could get a rotation
of 330 degrees on the potentiometer to 360 degrees on the rotor. I then
mounted the pot to the gear using a spring arm in case of overrun or limit
switch failure. This has worked for several years without any problems.
Attached is a photo of the Rotor showing the added gear. The Rotor is
mounted near the bottom of the tower for easy maintenance. It is the small
prop pitch with 24 vdc motor. It rotates a HyGain TH6 (@ 50ft.) and a 14 el
2M beam (@ 60ft). This is topped off by a lightening arrester which is a
grounded tri-band VHF/UHF Home brewed J-Pole using 1/2 & 1 in. copper
tubing. The complete antenna cluster rotates.
73's Jim (another one)
W5IFP
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com]On Behalf Of DF3KV
> Sent: Friday, September 03, 2010 7:59 AM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Antenna Rotor Speed
>
>
> Hi Jim,
>
> My drive motors usually are 3-phase 400V, so I have no problem to use
> automated ramping with a cycle inverter now.
> But first I need to add an additional position indicator to supply
> information to my electronic for that reason and to add point and shoot
> features.
> At present I only drive a selsyn together with the limit switches.
>
> http://ic2.pbase.com/g4/91/283791/2/64082622.IWWhlXiA.jpg
>
> http://ic2.pbase.com/g4/91/283791/2/64082562.ehwDr8mw.jpg
>
> http://ic2.pbase.com/g6/91/283791/2/68997594.xSfo0AWi.jpg
>
> 73
> Peter, DJ7WW
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Jim Thomson
> Sent: Freitag, 3. September 2010 13:47
> To: towertalk@contesting.com
> Subject: [TowerTalk] Antenna Rotor Speed
>
> Date: Thu, 2 Sep 2010 20:10:38 +0200
> From: "DF3KV" <df3kv@t-online.de>
> Subject: Re: [TowerTalk] Antenna Rotor Speed
>
>
> I found 40 seconds for one rotation real nice for contesting after I built
> my own rotator.
> I turned a christmas tree of 5 element yagis 20-10m + 3L FS on 40m without
> problems, but the stress on the double worm gearbox is quite heavy.
> I used finally a 50mm drive shaft to flange to the rotating mast, 25mm
> sheared off immediately the first time the rotation stopped.
> On my present installation with slew ring drive it takes 90 seconds to
> travel 360? which I find a bit too slow.
> Higher speeds are no problem for antennas built to survive storms.
>
> 73
> Peter, DJ7WW
>
> ## PWM is cheap. I bought a small pre-assembled PWM on a PC
> board... and it's rated for a max of 30 Vdc @ 50 A CCS. The pot on
> the board is removed... and replaced with 1-3 pots..and a switch.
> Then you
> can switch from slo-med-fast.... and back down again.
>
> ## The GH box is superb.. with it's ramp up/down and point
> and shoot feature.
>
> later... Jim VE7RF
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|
